Trigger mechanism for firearms



Dec. 3vl, 1929. F. F. BURTON 1,741,281

TRIGGER MECHANISM FOR FIREARMS Filed April 22. 1929 2 Sheets-Sheet l im@l 4 A Dec. 3l, 1929. 1 F. F. BURTON 1,741,281

TRIGG'ER MECHANISM FOR FIREARMS Y Filed April 22, 1929 2 Sheets-Sheet 2MIIHIIIIIIHHM I Patented Dec.` 31,' 1929 UNITED STATES Hiram"l orificeFRANK E. BURTON, oF MoUN'i` CARMEL, coNNEcrroUr, AssrGNoR To WINCHESTEREEPEATING ARMs co., or NEW HAVEN, coNNEcrIcUr, A coEroRArroN oE DELA-WARE TRIGGER MEHANISM FDR FIREARMS Application filed April 22, 1929.Serial No. 356,984.

This invention relates to an improvement in trigger-mechanisms forfirearms and particularly to that class of firearms in which thefiring-pin or its equivalent exerts a constant effort to swing the searout of cocking `engagement with it, in which position the said Sear isreleasably retained by the trigger; such a type of trigger-mechanismbeing shown in United States Patent No. 132,222, granted October 15,1872, to F. Von Martini, and

. of the r .tion of a firearm provided United States Patent No. 145,118,granted' December`2, 187 3,'to Daniel Moore'.

One 'of the `objects of my invention is ton reliable and durable trig-Vprovide a simple, ger-mechanism of the class described, constructed withparticular reference to smoothness and certainty of operation.

Another object of my invention is to provide a trigger-mechanism of theclass described having a smooth and adjustable travel ofthe trigger forreleasing the firing-element earm.

`With the above objects in view, my invention consists` in atrigger-mechanism for lirearms, having certain details of constructionand combinations of parts asA will be hereinafter described andparticularly recited in the claims.

In thel accompanying drawings:

Fig. 1 is a broken view, partly in elevation and partly in verticallongitudinal secwith my improved trigger-mechanism, the parts beingshown in the positions due them when the gun iscocked, ready for firing;

Fig. 2 is a corresponding view but show-i view of the assemblytaryside-arms 11 and 12 of a sheet-metal assembly-yoke 13 which is securedby means of a screw 14 to the underside of the receiver 15 of the arm.

The sear l0 above referred to is mounted at its forward end upon a pin16 extending transversely therethrough and between the the arms 11 and12 of the assembly-yoke 13.

At its rear end the sear 10 is formed with an upstanding Sear-nose 17,the reanupper corner 18 of which is forwardly and upwardly inclined andis adapted to engage a similarly inclined cam-like latching-shoulder 19formed upon the underside of the reciprocating tiring-pin 20,whichlatter is of usual form and requires no detailed description other thanto say that it is urged forward by the usual firing-pin spring 2l housedwithin it and is itselfhoused within a recipf with reference to thepivot-pin 16 that the forward urge of the tiring-pin 20 under thetension of its spring 21 tends to rock the Sear 1() downward against thecounter-urge of a scar-spring 24 mounted in a pocket 24(a in the upperface of a forwardly-olsetting portion 25 of the said sear 10 andimpinging at its upper end against the adjacent underface of thereceiver 15 (Fig. 2).

To releasably retain the sear 10 in position to prevent the forwardmovement of the ring-pin 20, as shown in Fig. l of the drawings, Iprovide a horizontal Sear-supporting shoulder 26 offsetting from therear face of the upper arm 27 of a pivotal trigger' 28 mounted upon apin 29 extending transversely between the depending complementary arms30 and 31 of the assembly-yoke 13, and formed with the usual curvedfingerpiece 32 projecting below the firearm.

The shoulder 26 of the trigger 28 is adapted to engage the uhderface 33of the sear 10 adjacent the rear wall of a vertical slot 34 formedtherein and receiving the upper end of the arm 27 of the trigger 28, asclearly shown in the drawings.

A trigger-spring 35 having its lower end seated in a pocket 36 of thetrigger fingerpiece 32 and havin its upper end encircling a linger 37depen ing from the rear wall of the assembly-yoke 13, exerts a constanteort to swing the trigger counter-clockwise and hence yieldinglymaintain the shoulder 26 thereof beneath the surface 33 of the scar,

` as shown in Fig. -1 of the drawings.

To limit the rearward movement of the upper end of the arm 27 ofthetrigger and hence the degree to which the shoulder'26 thereof underliesthe surface 33 of the Sear, I mount in the rear end of the said sear aninclined abutment-screw 38 reduced at its forward end te form astop-nger 39 projecting forward into the slot 34 and adapted l l to beengaged by the rear face ofthe arm 27 of the trigger to limit therearward swing thereof. 4

For the purpose of swinging the sear 10 downward completely out of thepath of the bolt 22 so as to, .permit its withdrawal from the firearm, Iform the upper forward face of the arm 27 of the .trigger 28 with acam-surface 40 adapted to co-act with a pin 41 extending transverselyacross the slot the firing-pin 2O and the inclination of the rear uppercorner 18 of the scar-nose 17, the urge' ofthe firing-pin spring 21 willact to cam the sear 10 downward yagainst the counter-urgeof the spring24 and thus permit the firingfpinto move forward and fire the cartridgein the chamber (not shown) of the firearm. The parts will have thusassumed the positions in which they are shown in Fig. 2 of the drawings.

Now, after the discharge of the arm as 4 above described, when thefiring-pluis restored to the position in which it is shown in Fig. 1,the scar-spring 24 will be permitted to act to swiingthe sear clockwiseto again interpose the Sear-nose 17 in' th'path of the of theadjusting-screw 38 projects into the slot 34 and lhence the degree towhich the said trigger must be pulled before releasing the sear. Thus,if it is desired to increase the degree to whichdthe trigger must oepulled before releasing the Sear, the screw 38 may be backed out of thesear so as to permit the shoulder 26 of the trigger to ride furtherunder the surface 33. If, on the other hand, a slighter degree oftrigger-pull isrdesired tol release the Sear, the screw 38 willbeadvanced so as to cause its stop-finger to project further within theslot 34 of the sear.y

I claim: l 1. In abolt-action firearm, the combinationwith avertically-slotted scar pivoted at ts forward end in the firearmstructure;

a firingipin formedin its underside with an inclined cam-likelatching-shoulder adaptedto be engaged by a portlonof the said scar andto cam the same into its releasing position; and a pivotal triggervhaving its upper end exten the said sear and provided with a shoulderadapted to udcrhe Aa portion of the said ment with the latching-shoulderof the said firing-pin against the counter-urge of thel by a portion ofthe said sear and to cam the sameinto its `releasing position; a pivotalthe slot-in the said scar and provided with a shoulder adapted tovunderlie a portion of the said sear to releasably hold the same inengagement with the latching-shoulder of the said firing-pin against thecounter-urge of the firingpin spring; and an adjustingscrew mounted inthe rear end of the said sear and projecting into the; slot therein toengage the upper end of th said trigger to adjustably limit the rearwardswing thereof.

In testimony whereof, I have signed this specification.

. FRANK F. BURTON.v

shoulder 19 of the firing-pin and in so doing f will also permit theupper arm 27 of the` trigger 28 to swing rearward under the urge of thetrigger-spring 35 and re-locate the shoulder 26 beneath the surface 33of the The parts are now restored to the positions shown in Fig: 1 ofthev drawin s, preparatory to anotherdischarge of the rearm.

It will be noted that the distacewhich the shoulder 26 of the trigger 28underlies the surface 33 of the Sear-10 is determined by the degree towhich the stopffi'nger ,39

ed into the slot'in sea'r to releasably hold the samein engage- ,triggerhaving its upper. -end extended into

